Electric switch



H. E. MILLER ELECTRIC SWITCH Nov. 28, 1933.

Filed Dec. 22, 1950 Inventor: Harry E. Miller, b9 His Attorney Patented Nov. 28, 1933 VUNITED STATES PATENT mes ELECTRIC SWITCH Harry E. Miller, Philadelphia, Pa., assignor to New 1 York General Electric, Company, a corporation of Application December 22,1930. 7

Serial N0. 503,870

3 Claims.

on live circuits although they are sometimes used to interrupt relatively small currents. Their principal function is to isolate circuit portions and apparatus so that they will be safe for inspection, maintenance and the like. It is, therefore, necessary for the safety of the personnel that a" switch, Whether mounted horizontally vertically or inclined, when once opened should remain open until an all clear signal is given for its closing and an intentional closing operation is performed. Consequently, the movable circuit controlling element of the switch, which is usually a rotatably mounted blade, must not,

of itself,be free to move from the circuit opening to the circuit closing position by reason of vibrations, shocks, snow or ice loads, the weight of the member itself, etc. However, for convenience of operation, itis essential that the cir- 5 cult controlling member be readily operable on the application of intentional force for the desired circuit opening and circuit closing movements. Accordingly, one object of my invention is to provide an improved and simple ar- '30 rangement which permits a predetermined circuit opening movement of the controlling memher and which then positively maintains the member in the circuit opening position until such time as it is desired further to operate the member. Other objects of my invention will appear hereinafter. My invention will be better understood from the following description when considered in connection with the accompanying drawing and its scope will be pointed out in the appended claims. In the accompanyingdrawing, Fig. 1 is'a side elevation of a single-pole, double-throw disconnecting switch embodying my invention. Fig. 2 is a side elevation with parts broken away of the hinge joint of the switch shown in Fig. 1, illustrating a blade stop embodying my invention. Fig. 3 illustrates the hinge joint of a disconnecting switch with a blade stop embodying a modiflcation of my invention. Figs. 4 and 5 are respectively side and end elevations of the hinge joint ofa disconnecting switch embodying another modification of my invention.

Referring now in particular to Figs. 1 and 2, a rotataloly mounted circuit controlling element, '55 such as the blade 10 of a single-pole double-throw disconnecting switch, is pivotally mounted at 11 on a hinge jaw such as a yoke 8 which is suitably supported by an insulator 12. The blade 10, may be of the truss type and, as shown, is arranged to engage tongue type contacts 13, it which are. mounted on insulators l5, 16 respectively. The whole switch structure is assembled on a base 9 which may be of any suitable character.

In accordance with my invention, I provide means iormaintaining the switch blade 10 in .a predetermined or desired circuit opening'position. As illustrated in Figs. land 2, this circuit opening position is, for example, half way between the jaw contacts 13 andle, that'is to say 90 rotation from each. 'As illustrated, my blade stop orholding device includes a member,

such as a pin 17, extending transversely of the blade 10 and carried thereby and resilient means, such as springs 18,19, mounted in the path of movement of the pin. 1'? for deflection thereby from aninitial condition on movement of the blade to the desired predetermined open position. As shown, springs 18, 19 are mounted on a supporting member or bracket 20 which may be suitably secured to the cap of the hinge supporting insulator 12. In order to avoid undue friction and wear, the pin 1'7 is preferably provided with a roller. 21 which, upon rotation of the blade in either direction, engages and rolls over one or the other or both of the springs 18 or 19.

At their adjacent free ends, the springs 18, 19 are shaped to receive the roller 21 by being bent inwardly to form a depression such as the V-shaped notch illustrated. Consequently, as

the blade 10 is moved to the position, indicated by. the broken lines in Fig. 2, intermediate its closed positions, one of the springs is depressed until the roller 21 rides over the corner 22 of the spring, whereupon the spring returns to its initial condition such that its free end, together with the free end of the other spring, forms a seat for the roller 21, as illustrated in Fig. 2. In this way, the switch is positively maintained in the desired circuit opening position without danger of movement therefrom. It is, however, readily movable from the open position by the application of an intentional force" at the end of the blade through the usual switch hook inserted in the eye 23 of the blade; This will be apparent because when the bladeis in the open position with the roller 21 seated between the free ends of the springs 18, 19, a forcible movement in either direction will cause the roller to ride up on the free end of one of the springs thereby deflecting this spring and permitting it to ride over the corner 22 thereof.

In the case of single-throw switches, it may be desirable not only to hold the blade in a predetermined position but also positively to limit the amount of circuit opening movement which the blade may have. For this purpose, I may provide an arrangement, such as is shown in Fig. 3, which is particularly adapted, for example, to single-throw switches. In this case, instead of springs 18 and 19 being shaped alike, the free end 24 of one of the springs 19 is bent into a position to form an abutment for the roller 21 such that the roller cannot ride up over the corner 22 of the spring 19.

In some cases, particularly where the question of electrical clearances with other switches or apparatus comes into consideration, it may be desirable to have the blade opening movement other than 90. In order to take care of this condition, I may adjustably position the resilient holding means or springs 18, 19 in order to provide the desired range of opening. This may be done, for example, as shown in Figs. 4 and 5 by having the bracket 20 built up of two parts, the base 25 and a pivoted member or yoke 2-3, which in order to prevent relative rotation, may have cooperating engaging toothed portions as shown. The base and yoke may be locked or clamped against rotation by suitable means such as a bolt 27. Thus, with the springs 18, 19 mounted on the yoke 26 which can be set in any desired position, it is possible to vary the circuit opening position in which the blade is held. For centering the roller 21 between the sides of the blade spacers 28 may be used as shown in Fig. 5.

While I have shown and described my invention in considerable detail, I do not desire to be limited to the exact arrangements shown, but seek to cover in the appended claims all those modifications that fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. Means for holding a pivotally mounted circuit controlling element in a predetermined position including a member carried by said element and extending transversely thereof and two resilient devices mounted adjacent the pivotal support of said element in the path of movement of said member for deflection thereby from an initial condition on movement of said element to the predetermined position, said resilient devices cooperating to form a depression for receiving said member on return to the initial condition with said element in said predetermined position whereby to maintain the element in said position.

2. Means for holding a rotatably mounted switch blade in an open circuit position including a member carried by the blade and extending transversely thereof and two oppositely inclined resilient elements mounted in the path of movement of said member, one of said elements being deflected from an initial condition by said member on circuit opening movement ofthe blade, and adjacent ends of said elements being'shaped to receive said member on a predetermined .circuit opening movement of the blade, the de fiected element returning to the initial condition when the blade has completed said movement whereby to maintain the blade in said position,

the other of said elements including means for positively limiting the circuit opening movement of the blade. y

3. Means for holding a rotatably mounted switch blade in an open circuit position including a member carried by the blade and extending transversely thereof and two oppositely inclined resilient elements mounted in the path of movement of said member for deflection thereby from an initial condition on circuit opening movement of the blade, the adjacent ends of said elements being shaped to receive said member on a predetermined circuit opening movement of the 1 blade and the deflected element returning to the 4 initial condition when the circuit opening movement of the blade is completed whereby to maintain the blade in an open circuitposition.

HARRY E. MILLER; l 

